Friday, December 21, 2007

For the first time in history, announced researchers this May, amajority of the world's population is living in urban environments.Cities—efficient hubs connecting international flows of people,energy, communications, and capital—are thriving in our global economyas never before. However, the same factors that make cities hubs ofglobalization also make them vulnerable to small-group terror andviolence.

Over the last few years, small groups' ability to conduct terrorismhas shown radical improvements in productivity—their capacity toinflict economic, physical, and moral damage. These groups, motivatedby everything from gang membership to religious extremism, have takenadvantage of easy access to our global superinfrastructure, revenuesfrom growing illicit commercial flows, and ubiquitously available newtechnologies to cross the threshold necessary to become terriblethreats. September 11, 2001, marked their arrival at that threshold.

Unfortunately, the improvements in lethality that we have already seenare just the beginning. The arc of productivity growth that lets smallgroups terrorize at ever-higher levels of death and disruptionstretches as far as the eye can see. Eventually, one man may even beable to wield the destructive power that only nation-states possesstoday. It is a perverse twist of history that this new threat arrivesat the same moment that wars between states are receding into thepast. Thanks to global interdependence, state-against-state warfare isfar less likely than it used to be, and viable only againstdisconnected or powerless states. But the underlying processes ofglobalization have made us exceedingly vulnerable to nonstate enemies.The mechanisms of power and control that states once exerted willcontinue to weaken as global interconnectivity increases. Small groupsof terrorists can already attack deep within any state, riding on thehighways of interconnectivity, unconcerned about our porous bordersand our nation-state militaries. These terrorists' likeliest point oforigin, and their likeliest destination, is the city.

Cities played a vital defensive role in the last major evolution ofconventional state-versus-state warfare. Between the world wars, therefinement of technologies—particularly the combustion engine, whencombined with armor—made it possible for armies to move at much higherspeeds than in the past, so new methods of warfare emphasized armoredmotorized maneuver as a way to pierce the opposition's solid defensivelines and range deep into soft, undefended rear areas. Theseincursions, the armored thrusts of blitzkrieg, turned an army's sizeagainst itself: even the smallest armored vanguard could easilydisrupt the supply of ammunition, fuel, and rations necessary tomaintain the huge armies of the twentieth century in the field.

To defend against these thrusts, the theoretician J. F. C. Fullerwrote in the 1930s, cities could be used as anchor or pivot points toengage armored forces in attacks on static positions, bogging down theoffensive. Tanks couldn't move quickly through cities, and if theybypassed them and struck too deeply into enemy territory, their supplylines—in particular, of the gasoline they drank greedily—would becomevulnerable. The city, Fuller anticipated, could serve as a vastfortress, requiring the fast new armor to revert to the ancient tacticof the siege. That's exactly what happened in practice during WorldWar II, when the defenses mounted in Leningrad, Moscow, and Stalingradplayed a major role in the Allied victory.

But in the current evolution of warfare, cities are no longerdefensive anchors against armored thrusts ranging through thecountryside. They have become the main targets of offensive actionthemselves. Just as the huge militaries of the early twentieth centurywere vulnerable to supply and communications disruption, cities arenow so heavily dependent on a constant flow of services from variouscentralized systems that even the simplest attacks on those systemscan cause massive disruption.

Most of the networks that we rely on for city life—communications,electricity, transportation, water—are overused, interdependent, andextremely complex. They developed organically as what scholars in theemerging field of network science call "scale-free networks," whichcontain large hubs with a plethora of connections to smaller and moreisolated local clusters. Such networks are economically efficient andresistant to random failure—but they are also extremely vulnerable tointentional disruptions, as Albert-Laszlo Barabasi shows in hisimportant book Linked: The New Science of Networks. In practice, thismeans that a very small number of attacks on the critical hubs of ascale-free network can collapse the entire network. Such a collapsecan occasionally happen by accident, when random failure hits acritical node; think of the huge Northeast blackout of 2003, whichcaused $6.4 billion in damage.

Further, the networks of our global superinfrastructure are tightly"coupled"—so tightly interconnected, that is, that any change in onehas a nearly instantaneous effect on the others. Attacking one networkis like knocking over the first domino in a series: it leads tocascades of failure through a variety of connected networks, fasterthan human managers can respond.

The ongoing attacks on the systems that support Baghdad's 5 millionpeople illustrate the vulnerability of modern networks. Over the lastfour years, guerrilla assaults on electrical systems have reducedBaghdad's power to an average of four or five hours a day. And theinsurgents have been busily finding new ways to cut power: no longerdo they make simple attacks on single transmission towers. Instead,they destroy multiple towers in series and remove the copper wire forresale to fund the operation; they ambush repair crews in order toslow repairs radically; they attack the natural gas and waterpipelines that feed the power plants. In September 2004, one attack onan oil pipeline that fed a power plant quickly led to a cascade ofpower failures that blacked out electricity throughout Iraq.

Lack of adequate power is a major reason why economic recovery hasbeen nearly impossible in Iraq. No wonder that, in account afteraccount, nearly the first criticism that any Iraqi citizen levelsagainst the government is its inability to keep the lights on.Deprived of services, citizens are forced to turn to local groups—manyof them at war with the government—for black-market alternatives. Thismoney, in turn, fuels further violence, and the government loseslegitimacy.

Insurgents have directed such disruptive attacks against nearly allthe services necessary to get a city of 5 million through the day:water pipes, trucking, and distribution lines for gasoline andkerosene. And because of these networks' complexity andinterconnectivity, even small attacks, costing in the low thousands ofdollars to carry out, can cause tens of millions and occasionallyhundreds of millions of dollars in damage.

Iraq is a petri dish for modern conflict, the Spanish Civil War of ourtimes. It's the place where small groups are learning to fight modernmilitaries and modern societies and win. As a result, we can expect tosee systems disruption used again and again in modernconflict—certainly against megacities in the developing world, andeven against those in the developed West, as we have already seen inLondon, Madrid, and Moscow.

Another growing threat to our cities, commonest so far in thedeveloping world, is gangs challenging government for control. Forthree sultry July days in 2006, a gang called PCC (Primeiro Comando daCapital, "First Command of the Capital") held hostage the 20 millioninhabitants of the greater São Paulo area through a campaign ofviolence. Gang members razed police stations, attacked banks, riotedin prisons, and torched dozens of buses, shutting down atransportation system serving 2.9 million people a day.

The previous May, a similar series of attacks had terrified the city."The attackers moved on foot, and by car and motorbike," wrote WilliamLangewiesche in Vanity Fair. "They were not rioters, revolutionaries,or the graduates of terrorist camps. They were anonymous young men andwomen, dressed in ordinary clothes, unidentifiable in advance, andindistinguishable afterward. Wielding pistols, automatic rifles, andfirebombs, they emerged from within the city, struck fast, andvanished on the spot. Their acts were criminal, but the attackers didnot loot, rob, or steal. They burned buses, banks, and publicbuildings, and went hard after the forces of order—gunning down thepolice in their neighborhood posts, in their homes, and on the streets."

The violence hasn't been limited to São Paulo. In December 2006, acopycat campaign by an urban gang called the Comando Vermelho ("RedCommand") shut down Rio de Janeiro, too. In both cases, the gangsfomenting the violence didn't list demands or send ultimatums to thegovernment. Rather, they were flexing their muscles, testing theirability to challenge the government monopoly on violence.

Both gangs had steadily accumulated power for a decade, helped in partby globalization, which simplifies making connections to themultitrillion-dollar global black-market economy. With these newconnections, the gangs' profit horizon became limitless, fueling rapidexpansion. New communications technology, particularly cell phones,played a part, too, making it possible for the gangs to thrive asloose associations, and allowing a geographical and organizationaldispersion that rendered them nearly invulnerable to attack. The PCChas been particularly successful, growing from a small prison gang inthe mid-nineties to a group that today controls nearly half of SãoPaulo's slums and its millions of inhabitants. An escalatingconfrontation between these gangs and the city governments appearsinevitable.

The gangs' rapid rise into challengers to urban authorities issomething that we will see again elsewhere. This dynamic is already atwork in American cities in the rise of MS-13, a rapidly expandingtransnational gang with a loose organizational structure, a propensityfor violence, and access to millions in illicit gains. It already hasan estimated 8,000 to 10,000 members, dispersed over 31 U.S. statesand several Latin American countries, and its proliferation continuesunabated, despite close attention from law enforcement. Like the PCC,MS-13 or a similar American gang may eventually find that it hassufficient power to hold a city hostage through disruption.

The final threat that small groups pose to cities is weapons of massdestruction. Though most of the worry over WMDs has focused on nuclearweapons, those aren't the real long-term problem. Not only is the vastmanufacturing capability of a nation-state required to produce thebasic nuclear materials, but those materials are difficult tomanipulate, transport, and turn into weapons. Nor is it easy toassemble a nuke from parts bought on the black market; if it were,nation-states like Iran, which have far more resources at theirdisposal than terrorist groups do, would be doing just that instead ofresorting to internal production.

It's also unlikely that a state would give terrorists a nuclearweapon. Sovereignty and national prestige are tightly connected to theproduction of nukes. Sharing them with terrorists would grant immensepower to a group outside the state's control—the equivalent of givingOsama bin Laden the keys to the presidential palace. If that isn'tdeterrent enough, the likelihood of retaliation is, since states,unlike terrorist groups, have targets that can be destroyed. Theresult of a nuclear explosion in Moscow or New York would veryprobably be the annihilation of the country that manufactured thebomb, once its identity was determined—as it surely would be, since noplot of that size can remain secret for long.

Even in the very unlikely case that a nuclear weapon did end up interrorist hands, it would be a single horrible incident, rather thanan ongoing threat. The same is true of dirty bombs, which disperseradioactive material through conventional explosives. No, the reallong-term danger from small groups is the use of biotechnology tobuild weapons of mass destruction. In contrast with nucleartechnology, biotech's knowledge and tools are already widelydispersed—and their power is increasing exponentially.

The biotech field is in the middle of a massive improvement inproductivity through advances in computing power. In fact, the curvesof improvement that we see in biotechnology mirror the rates ofimprovement in computing dictated by Moore's Law—the observation,borne out by decades of experience, that the ratio of performance toprice of computing power doubles every 24 months. This means thatincredible power will soon be in the hands of individuals. Universityof Washington engineer Robert Carlson observes that if current trendsin the rate of improvement in DNA sequencing continue, "within adecade a single person at the lab bench could sequence or synthesizeall the DNA describing all the people on the planet many times over inan eight-hour day." And with ever tinier, cheaper, and more widelyavailable tools, a large and decentralized industrial base that ishiring lab techs at a double-digit growth rate, and the activetransfer of knowledge via the Internet (the blueprints of the entiresmallpox virus now circulate on the Web), biotech is too widelyavailable for us to contain it.

In less than a decade, then, biotechnology will be ripe for thewidespread development of weapons of mass destruction, and it fits therequirements of small-group warfare perfectly. It is small,inexpensive, and easy to manufacture in secret. Also, since dangerousbiotechnology is based primarily on the manipulation of information,it will make rapid progress through the same kind of amateur tinkeringthat currently produces new computer viruses. Terrorists also have agrowing advantage in delivering bioweapons. The increasing porousnessof national borders, size of global megacities, and volume of airtravel all mean that the delivery and percolation of bioweapons willbe fast-moving and widespread—potentially on several continents at once.

It is almost certain that we will see repeated, perhaps incessant,attempts to deploy bioweapons with new strains of viruses or bacteria.Picture a Russian biohacker who, a decade from now, designs a new,deadly form of the common flu virus and sells it on the Internet, justas computer viruses and worms get sold today. The terrorist group thatbuys the design sends it to a recently hired lab tech in Pakistan, whoperforms the required modifications with widely available tools. Theproduct then ships by mail to London, to the awaiting "suicidevectors"—men who infect themselves and then board airplanes headed toworld destinations, infecting passengers on the planes and in crowdedterminals. The infection spreads quickly, going global in days—longbefore anyone detects it.

It's very possible that many cities will fall in the face of suchdeadly threats. Megacities in the developing world—which often,because of their rapid growth, widespread corruption, and illegitimategovernance, aren't able to provide security or basic services fortheir citizens—are particularly vulnerable. However, cities in thedeveloped world that properly appreciate the threats arrayed againstthem may devise startlingly innovative solutions.

In almost all cases, cities can defend themselves from their newenemies through effective decentralization. To counter systemsdisruption, decentralized services—the capability of smaller areaswithin cities to provide backup services, at least on a temporarybasis—could radically diminish the harmful consequences ofdisconnection from the larger global grid. In New York, this wouldmean storage or limited production capability of backup electricity,water, and fuel, with easy connections to the delivery grid—at theborough level or even smaller. These backups would then provide ameans of restoring central services rapidly after a failure.

Similarly, cities may combat networked gangs by decentralizing theirown security. Cities have long maintained centralized police forces,but gangs can often overwhelm them. Many governments are respondingwith militarized police: China is building a million-man paramilitaryforce, for example; and even in the United States, the use of SWATteams has increased from 3,000 deployments a year in the 1980s to50,000 a year in 2006. But militarized police may too easily become anarmy of occupation, and, if corrupt, as they are in Brazil, they maybecome enemies of the state along with the gangs.

A better solution involves local security forces, either locallyrecruited or bought on the marketplace (such as Blackwater), which canbe powerful bulwarks against small-group terrorism. Such forces maybecome a vital component in our defense against bioterrorism, too,since they can enforce local containment—and since large centralizedservices, like the ones we have today, might actually accelerate thepropagation of bioweapons. Still, if improperly established, localforces can also become rogue criminal entities, like the AutodefensasUnidas de Colombia and the militias in Rio de Janeiro. Governmentsneed to regulate them carefully.

In the future, we probably won't know exactly how we will be attackeduntil it happens. In highly uncertain situations like this,centralized solutions that emphasize uniform responses will oftencollapse. Heterogeneous systems, by contrast, are unlikely to failcatastrophically. Moreover, local innovation—supplemented by amarketplace in goods and services that improve security, detection,monitoring, and so on—is likely to develop responses to threatsquickly and effectively. Other localities will copy those responsesthat prove successful.

In June 2007, the FBI and local law enforcement halted a plot to blowup the John F. Kennedy International Airport's fuel tanks and feederpipelines. This was another great example of how police forces, ifused correctly, can defuse threats before they become a menace [see"On the Front Line in the War on Terrorism"].http://www.city-journal.org/html/17_3_preventing_terrorism.html

However, our current level of safety will not last. The selection ofthe target demonstrated clearly that future attackers will takeadvantage of our systems' vulnerability to disruption, which willsharply increase the number of potential targets. It also showed thatthese threats can emerge spontaneously from small groups unconnectedto al-Qaida. More and more attempts will come, with higher and higherrates of success. Our choice is simple: we can rely exclusively on ourcurrent security systems to stop the threats—and suffer theconsequences when they don't—or we can take measures to mitigate theimpact of these threats by exerting local control over essential services.